Citation

Material Information

Title:
Bathymetric Mapping and Lake Shoreline Characterization at Green Lakes State Park
Creator:
Nicole Insolia
Justin Stroup
Rachel Lee
Aidan Becker
Publication Date:

Subjects

Subjects / Keywords:
Green Lakes State Park
Bathymetric map
Tufa
Shoreline characterization
Green Lake
Round Lake
Fayetteville, NY
Sonar imaging
Lake bathymetry

Notes

Abstract:
Green Lakes State Park, located in Fayetteville, NY consists of two meromictic lakes: Green Lake and Round Lake. Green Lake is the larger and deeper of the two which reside at the base of a gorge formed from a glacial river during the last Ice Age (~15 ka). The origin of these lakes is not entirely known, but it is inferred that the formation of these glacial plunge pools is associated with large waterfalls. The meromictic nature of these lakes indicates that deep, intermediate, and shallow waters within the lake remain separate and do not mix. Dissolved solids, such as calcium, are concentrated in the groundwater here, which regularly outlet into both lakes. The presence of calcium carbonate ions in the groundwater contribute to lake precipitate in the form of the mineral calcite, which has accumulated as a mineral crust enveloping parts of Green Lake’s shoreline and deep beneath its surface. Occasionally, sediment and debris fall into the lake, which become encapsulated in the mineral crust, forming what is known as a tufa. Tufa are prevalent throughout the lakes, particularly at groundwater outlets. Currently, there is limited information about the bathymetry of these lakes as they are significantly deep and understudied. Our project sought to provide a more in-depth look at the topography of the lake bottom, sides, and transition to shorelines. Additionally, this research aimed to identify locations of tufa development and evaluate if tufa localities and concentrations of coniferous trees correspond. We collected sonar data using a Humminbird SOLIX side scanning sonar system in August, 2020. The data was processed with Reefmaster software and track depths were edited to ensure the interpreted sonar reflections accurately represented lake bottom depths. We produced a high-resolution bathymetric map of the lake bottom. Side scan sonar data was processed using Sonar TRX software and tufa were visually identified. We were also able to detect shoreline steepness, vegetation and woody debris (trees). We provide the first high resolution bathymetric map of the lake and were able to identify tufa in known locations and also document many lesser or unknown locations of tufa formation.
Acquisition:
Collected for SUNY Oswego Institutional Repository by the online self-submittal tool. Submitted by Nicole Insolia.

Record Information

Source Institution:
SUNY Oswego Institutional Repository
Holding Location:
SUNY Oswego Institution
Rights Management:
All applicable rights reserved by the source institution and holding location.

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!"#$%&'( 4 ) Methods : Prior orthoimagery, aerial imagery, field observation, and sonar were used to map vegetation types, map lake bathymetry, and identify tufa locations . Prior imagery : We used orthoimagery from 2003 ( 24 inch resolution color infrared ) to delineate vegetative cover in ArcMap 10 . 7 . 1 . Field observations and Aerial Imagery : We used recent Google Earth imagery from 2019 to observe vegetative cover type and identify tufa localities . Visible tufa deposits were verified in the field . Bathymetry and Sonar Mapping : We used a SOLIX 12 CHIRP MEGA SI+ G 2 50 / 83 / 200 / 455 / 800 kHz & 1 . 2 MHz (Fig . 3 ) to collect down looking and side scan sonar images . We used Reefmaster 2 . 0 for bathymetric mapping and Sonar TRX to process and visualize the sonar data . 3 ) Study Area : About 11 miles south of Oneida Lake, two glacially scoured plunge pools (Green Lake and Round Lake) are situated in Green Lakes State Park (Fig . 1 a, b) . The landscape is mantled by glacial till from the retreat of the last ice sheet and the underlying bedrock of the site sits at the contact between argillaceous dolostone beds of the Syracuse Formation and Vernon Shale (Thompson, Ferris, & Smith, 1990 ) . The lake water is a piercing blue green and the shore is vegetated (Fig . 2 ) . Skirting the shore and extending into the water of Green Lake, there are calcite mineral crusts precipitating in the water (Fig . 2 ) . These structures, called tufa, tend to form in areas where the calcium carbonate ion rich groundwater is interacting with the lake water . 1 ) Abstract : Green Lakes State Park, located in Fayetteville, NY consists of two meromictic lakes : Green Lake and Round Lake . Green Lake is the larger and deeper of the two which reside at the base of a gorge formed from a glacial river during the last Ice Age (~ 15 ka) . The origin of these lakes is not entirely known, but it is inferred that the formation of these glacial plunge pools is associated with large waterfalls . The meromictic nature of these lakes indicates that deep, intermediate, and shallow waters within the lake remain separate and do not mix . Dissolved solids, such as calcium, are concentrated in the groundwater here, which regularly outlet into both lakes . The presence of calcium carbonate ions in the groundwater contribute to lake precipitate in the form of the mineral calcite, which has accumulated as a mineral crust enveloping parts of Green Lake's shoreline and deep beneath its surface . Occasionally, sediment and debris fall into the lake, which become encapsulated in the mineral crust, forming what is known as a tufa . Tufa are prevalent throughout the lakes, particularly at groundwater outlets . Currently, there is limited information about the bathymetry of these lakes as they are significantly deep and understudied . Our project sought to provide a more in depth look at the topography of the lake bottom, sides, and transition to shorelines . Additionally, this research aimed to identify locations of tufa development and evaluate if tufa localities and concentrations of coniferous trees correspond . We collected sonar data using a Humminbird SOLIX side scanning sonar system in August, 2020 . The data was processed with Reefmaster software and track depths were edited to ensure the interpreted sonar reflections accurately represented lake bottom depths . We produced a high resolution bathymetric map of the lake bottom . Side scan sonar data was processed using Sonar TRX software and tufa were visually identified . We were also able to detect shoreline steepness, vegetation and woody debris (trees) . We provide the first high resolution bathymetric map of the lake and were able to identify tufa in known locations and also document many lesser or unknown locations of tufa formation . Figure 1 a) Green Lakes State Park location, Round Lake (left) and Green Lake (right) . (Imagery, Google Earth October 10 th , 2019 ) 2 ) Problem : The guiding questions in this research are : A) What is the detailed bathymetry of Green Lake? B) Can we identify previously known and unknown tufa locations using sonar? C) Is there a correlation between tufa deposits (locations of ground water influx) and vegetation types on the land surface? N N N Figure 2 ) Left : Photos of Green Lake shoreline, August 2020 . Right : Magnified aerial view of prominent tufa in the southern portion of Green Lake . Along the shoreline, the water is very clear, allowing for shallow tufa structures to be identified through the water . The calcite mineral crusts encrust the shore and debris (i . e . tree branches) in the water . Figure 1 b) Surficial geology map depicts glacial setting of Green Lakes State Park, Fayetteville, NY (Muller & Cadwell, 1986 ) . Bathymetric Mapping and Lake Shoreline Characterization at Green Lakes State Park INSOLIA, Nicole., STROUP, Justin., LEE, Rachel., and BECKER, Aidan., Department of Atmospheric and Geological Sciences, State Un iversity of New York at Oswego, Oswego, NY 13126 Figure 3 ) Utilizing the Humminbird SOLIX software to collect side scan sonar data on Green Lake . Screen view portraying contours (left) and visible tree branches along the shore and debris beneath the surface (right) . !"#$%&'( !"#$%&' 6) Discussion/Conclusion: 7) Future Work: 5 ) Results : Below are the results of our bathymetric mapping (Fig . 4 ), sonar imaging (Fig . 5 ), and vegetation mapping (Fig . 6 ) . 200m N N N Figure 4 . B athymetric mapping . Left : Data collection track color shaded by lake depth . Right : Detailed bathymetric map using processed return data . Major contour interval = 10 m (~ 33 ft) and minor contour interval 2 . 5 m (~ 8 . 2 ft) . The maximum depth of Green Lake is approximately 52 . 7 m (~ 173 ft) . H) Three small tufa deposits, shadows indicate vertical growth . F) Known tufa deposit (Fig . 2 C) jutting out from the lakeshore . Tree branches and trunks are also visible atop the tufa deposit . Encrusting is also visible . 413 ft I) Newly identified tufa deposit growing outward from an area with woody debris. A) Two known tufa deposits . (Fig . 2 B) overlain by woody debris . B & C) Newly identified tufa deposits . 0.0 Ð 28.7m 0.0 Ð 23m F F D) This known tufa deposit (Fig . 2 A) is slightly deeper and woody debris is visible atop the deposit . Shadowing shows the deposit is growing out into the lake . 0.0 Ð 84.5m Figure 5 . Sonar imaging of Green Lake . We imaged the parameter of the lake to identify locations of tufa and map woody debris . Reflected sonar waves portray detailed views of tufa geometries . We were able to locate and examine known tufa deposits (blue circles) and utilize this information to identify other less obvious tufa formations (red diamonds) . L) The largest cohesive tufa known to exist at Green Lake is located at "Deadman's Point" . This image highlights the complexity of tufa deposits and clearly shows characteristic tufa geometry . 0.0 Ð 45.9m 0.0 Ð 24.5m K) A majority of the Green Lake shoreline contains no tufa highlighting the rarity of the formations. Woody debris such as fallen tree branches, sticks, and logs are abundant. This image portrays the varying debris visible along the submerged shore. Figure 6. Vegetation mapping of Green Lakes State Park. Remote sensing was incorporated to document vegetative cover surrounding Green Lake and Round Lake. Left) 24 Ð inch resolution color i nfrared orthoimage from the town of Manlius, NY (2003). New York State Plane, Central Zone, NAD 83, US Survey Feet (gis.ny.gov). Brightness temp era tures correspond with varying vegetation types. Right) Vegetation mapping differentiating coniferous and deciduous trees. Mixed trees represent a mixture of both types. Green Lake bathymetry same as Fig . 4. ! We provide the first high resolution bathymetric map of Green Lake. ! We confirmed the locations of known tufa deposits throughout the lake and documented their morphology with sonar. ! Using the known tufa localities, we identified ten less prominent tufa formation areas. We imaged and mapped their locations. ! Correspondence between coniferous forest and tufa locations is imperfect as represented by broad scale vegetation mapping. ! The combination of remote sensing techniques was powerful for constructing a map of the lake bathymetry, identifying tufa, and understanding Green Lake's association with the surrounding landscape. 8 ) Acknowledgements : We thank SUNY Oswego for their support by funding this project through a RISE Faculty Student Challenge Grant . We also thank Green Lakes State Park for permission and field support to conduct this research, and Richard Frieman for his dedicated and continual technological support throughout this project . ! Refine bathymetric mapping by collecting additional depth data perpendicular to prior collected tracks. ! Acquire shoreline sonar images in clockwise and counterclockwise directions to view tufa deposits in maximum detail. This may reveal additional tufa formation areas. ! Verify vegetation mapping with drone images of the modern lake shore. Drone images may reveal smaller scale vegetation changes that correlate with tufa (known locations of groundwater discharge). ! Attempt to identify the lesser known tufa deposits using drone imagery. A A 14.1 Ð 33.3m C C B D 11.8 40.5m B 22.5 Ð 41.7 m D E 18.5 37.6m H 0.0 Ð 13.8m I H I E 0.0 Ð 44.5m E) Small tufa encrusting woody debris . K K L J) Newly identified tufa deposits with woody debris submerged along the shore . J J G G 0.0 Ð 17.2m 0.0 Ð 28.6m L G) Newly identified tufa encrusting trees. !"#$%&'( 9) Citations: Thompson, J. B., Ferris, F. G., & Smith, D. A. (1990). Geomicrobiology and Sedimentology of the Mixolimnion and Chemocline in Fayetteville Green Lake, New York. Palaios , 5 (1), 52 75. Muller, E. H., & Cadwell, D. H. (1986). Surficial Geologic Map of New York, Finger Lakes Sheet. New York State Geological Survey.